If memory serves, it's not in the '08. I recall this once being a requirement, but it caused so many problems as it forced the front faces of all electrical equipment to be brought out to the same plane.
Image several 4" panels, 20" MDP, 24" MCC and a 30" transformer on a wall. The requirement said the front faces were all to be on the same plane. Made installing switchgear a royal PITA.
So I think it got removed, but I can't locate it in any of the older codes.
Any easy way to find it is to ask the inspector for a Code reference.